[ggggbmw]

Although this is apparently fairly common on newer BMW's, I haven't seen much on it in the 2 section.

A few weeks back I was starting to get 'Low Battery' warnings on the iDrive when I started the car, and sometimes when I turned it off. Sometimes it said there was a drain on an accessory circuit, and I should unplug things. I had a tiny flashlight in the back console socket, so I unplugged that. Then it started saying to make longer drives, or to charge the battery. It also said it would start to disable electrical services. I noticed a few things, like the interior lights didn't always come on. But the car still started, and the seat heaters ran, and I didn't think too much about it. Figured it would sort itself out.

This was about a perfect storm of battery drains. It was the coldest average temp that week in 100 years, with lows around -20F, and rarely above zero. The car had been parked for several days, and then only short 5 mile drives to work and back. I also don't lock the car in the garage, which apparently lets iDrive run longer causing further drains.

What finally got my total attention was coming out of work on a -10F day, and the car was completely dead. Comfort Access was totally unresponsive. Pulled the fob out of my pocket and tried the buttons. Also dead. (The whole reason for CA is so that I don't have to take my gloves off on cold days like that!) Finally pulled the real key out of the fob so I could get in the car and call AAA. (-30F wind chill, so I wanted inside.) Get in and the car was just dead. No lights. Nothing.

Well, maybe not quite dead. It was dark, and I happened to notice that the text on the Start button was lit.

Hmmm. Put my foot on the brake, pushed the button, and it started right up! Woohoo!

The car turned off so many services that the only thing left running was the Start button. It got me home, but boy, that was cutting it close. Time to take those 'charge the battery' messages seriously!

I have a Deltran charger. So when I got home I hooked it up to the convenient battery jump posts under the hood and let it charge overnight. It showed a full charge in the morning. The car has been perfect ever since.

So, a few comments:
First, take those warning seriously. This car will get aggressive about trying to protect it's battery charge. Which I guess is better than letting the battery run down to the point it won't start.

Second, I'm a bit annoyed that if the car can track charge that closely, that it can't put the alternator in a higher charge range when the battery is low. Maybe bump the idle and change shift points to maintain a higher RPM. They could even put some cranky German admonishment warning messages that it has to run higher RPM to charge the low battery.

Third, seriously, I have to hook up my fancy $50K car to a charger when it gets cold out? I haven't had to do that in 30 years, with any of the other mundane cars I've driven.

And finally some questions:
How many of you have experienced this? I know it's even colder for many of the Canadians on the forum. Or do you just drive longer? Or hook it up the charger sooner?

Also, could my battery just be getting old? I have an early model, with a 12/2013 build date, so the battery is now 4+ years old. That's nearing expected life span. How many of you have had to replace yours?

Thanks for reading my rambling.

[ggggbmw]

Argh. No battery posts two days ago when I started composing this thread. I even ran a search to check. And just today someone starts a whole new thread on battery charging, before I notice and posted mine. <sigh>

Sorry for the thread pollution......

[DanG]

I have a 12/03/13 build. My car has only 28,900 miles on it. I have never had a low battery warning. But my wife’s Golf had to get its battery replaced after four years. It was completely dead and AAA replaced the battery.

[wdc330i]

As I wrote in the other thread, all my BMWs have needed a new battery after 4 years.

[Maynard]

"They could even put some cranky German admonishment warning messages that it has to run higher RPM to charge the low battery."

Score one (more) for the car being smarter than the owners. Like, you would have listened if it was in German? But seriously, thanks for the post, it is reassuring that there is as much reserve capacity as there is (THAT would have been my take on this - holy crap they built a good system that I can drive for days w/ a warning in sub zero, and it will still save my ass by starting).

[XutvJet]

When it gets that cold, you're driving minimal distance, aren't driving the car much, etc., you're going to have to hook the car up to a battery tender, preferably something specifically designed for AGM type batteries like the one in your M235. Something like the $60 CTEK MUS 4.3 is what you want. BMW sells a rebranded version of this for twice as much.

I've owned my M235 for 2 years and got my first battery discharged warning a couple weeks back after an extreme cold spell in Kansas City. I got the CTEK MUS 4.3 and hooked it up for one night. Temps came back up shortly after that and I haven't had a single warning.

This is just a way of life with these cars if you live somewhere that can get extremely cold. A battery tender will also extend the life of that expensive battery and running the tender everyone once in a while during the winter is cheap insurance.

[bimmer_girl89]

Where I'm from, average winter temp would range from -25C to -40C + windchill. As per my dealers advice, I should plug the trickle charger once temp drops -20C. I have an underground parking at home but when I'm at work, the car sits outside for 9-10hrs. I plug it in if it's sitting outside and have never had any issues (even with my 2 previous F30's).

I guess what I'm wondering is if your car came equipped with a trickle charger when you bought it. Mine came with one from factory. I find that as long as you plug the trickle charger, you shouldn't have any issue.

[Bahuba]

I too was getting the excessive battery drain warning and even after long drives I would still get this warning, but only on colder days -5 to -15C. Took it into the dealer and in my case the battery was at fault (returning some error code) so it was replaced under warranty and I've had no warnings since.

[stevenvillatoro]

I had to have the battery replaced when my '18 was just a week old.

Apparently, BMW prevents its batteries from being recharged when they reach a certain level of depletion, regardless of their age.

[MarcoZandrini]

Batteries are damaged when their charge levels gets below a certain point. It’s chemistry. These cars are rolling computers so their “consumption” of ejuice is high. My solution is to take the car on a 20 mile+ trip at highway+ speeds at least once a week.This charges the battery and gets the driveline up to full operating temperatures. Cars don’t like short trips.

[TajoMan]

I think it's around 10.5V.
If the battery voltage is below that, it's done.
It is fine for short period but no load voltage is lower than 10.5V, it does not take charge anymore.

[P2]

My battery is just over 2 years old. First I receive the message to drive longer or recharge. Odd because I just finished 2 1hr drives. Hooked to up to the CTEK MUS 4.3. The first attempt was unsuccessful. Reconnected and it completed in 6 hours. After sitting for a few hours I still got the message. Then I got the discharging message. I got some minor pushback from the SA. I said just test it and we'll know. Tested, needed a new batters. Installed on Wednesday.
My last battery was going strong after 6 years ?. I'm hopping for better luck with this new one.

[Sindarin]

Kind of surprised no one has posted this yet. All you want to know about battery state of charge, intelligent battery sensor, and startability limit.

https://www.newtis.info/tisv2/a/en/f...ttery/BdzoqEna

[ggggbmw]

Originally Posted by XutvJet

.... Something like the $60 CTEK MUS 4.3 is what you want. BMW sells a rebranded version of this for twice as much.

I've owned my M235 for 2 years and got my first battery discharged warning a couple weeks back after an extreme cold spell in Kansas City.

If I was buying a new charger, the CTEK would be nice. But, I already have the Deltran (Battery Tender Plus Charger #021-0128). Deltran specifically states it supports AGM batteries. If I used it all the time I might consider the CTEK, but a few times a year, with a 12 hour max, and I think the Deltran will be fine.

btw, I think it was the same cold spell that got me. I'm 6 hours north up I-35 from you.

Originally Posted by bimmer_girl89

I guess what I'm wondering is if your car came equipped with a trickle charger when you bought it. Mine came with one from factory. I find that as long as you plug the trickle charger, you shouldn't have any issue.

A charger from the factory must be a unique Canadian option. Makes sense, and you definitely get different options than we do in the US. It would be a nice option for us in Minnesota.

[3.0L]

I've experienced 2 "Battery Low" warnings since I bought my 2 in 2014. In both cases, the car had been sitting for 2 or 3 weeks in a nice, warm garage.
I simply wasn't driving the car enough, plus too many short trips. Apparently, the car does use a fair amount power when just sitting.

On the up side, the remedy to the problem was quite enjoyable - simply take the car out for a long, frisky drive! And more often!

[raleedy]

Why not just keep a LiIon battery pack on hand for jump starts?

[Tpeterson]

Originally Posted by Sindarin

Kind of surprised no one has posted this yet. All you want to know about battery state of charge, intelligent battery sensor, and startability limit.

https://www.newtis.info/tisv2/a/en/f...ttery/BdzoqEna

With all those sensors and modules involved with determining the state of charge,it's no wonder there is a large parasitic drain while the cars sit.

[Cumberlandjames]

Originally Posted by bimmer_girl89

Where I'm from, average winter temp would range from -25C to -40C + windchill. As per my dealers advice, I should plug the trickle charger once temp drops -20C. I have an underground parking at home but when I'm at work, the car sits outside for 9-10hrs. I plug it in if it's sitting outside and have never had any issues (even with my 2 previous F30's).

I guess what I'm wondering is if your car came equipped with a trickle charger when you bought it. Mine came with one from factory. I find that as long as you plug the trickle charger, you shouldn't have any issue.

Just curious as to where the charger was mounted or was it just in the car loose? Never heard of one being included, mine didn't come with one.
thanks

[RvR]

Hi guys,

We have two things going on here, newer cars have high “parasitic” electrical loads, even when turned “off." The other, the effort to meet ever tighter CAFE rules, with all the unwanted side effects, e.g, electrically power assisted steering, auto-stop, upshift lights, et al., and the case here, no charging unless the car brakes or decelerates.

Take a look at the Efficient Dynamics gauge, the red section gives you theoretical MPG, and seems to work like a vacuum gage. On the left side of the sweep, however, note there’s a blue section with a picture of a battery on it. I believe that tells you when it’s charging, and note it doesn’t spend a lot of time in the blue.

Here’s a Road & Track article about V8 BMWs killing batteries:

http://www.roadandtrack.com/car-cult...ns-bmw-n63-v8/

The short version, unless you’re braking-slowing, the car doesn’t charge the battery. Short trips, cold (or vey hot) weather, all add up to battery killers.

I had a friend with an M235i that lived about 2 miles from work, and she killed a battery about every other year, until the dealer got so frustrated they gave her a battery maintainer. Then she’d forget to hook it up. I suggested making an iPhone reminder to do it once a week, and voila, no more dead batteries.

When doing my M240i ED delivery floor pickup, after looking at the car’s exterior, at least the first thing my BMW rep recommended was to hook the car up to the building power via the under-hood posts, while we went through the features. I was a little surprised by this on a brand-new car, but thought it indicative of high parasitic load. They use a flat cable run into a round plate in the floor of the turntable. There’s no maintainer down in the floor, I looked, it must be wired to some bank apparatus — I think there are five turntables, If I remember correctly.

Later, while looking at the Welt display floor cars, I spied a CTek 25000 sitting in the passenger seat of the M4, not hooked up, but made note of it, and took a photo (I tried attaching it.) The 25000 can deliver far more current than the 4.3, but for normal use the 4.3 should be ideal. I expect they use the 25000 because the visitors play with the display floor cars all day long, running the batteries down, and they have to move it from car to car to charge them back up.

I had a loaner 3 series one very cold week, with lots of days under 0F. When I got in it, it immediately sent the low charge message, and turned over quite slowly. I imagine the dealers are challenged with keeping undriven cars charged up in super cold weather. I have a CTek 3300 and hooked the 3er up to it when I got home. The first time it was on for about 35 hours and never got to maintenance mode. A day later I hooked it up again for overnight, and that AM it was in maintenance, and no more low charge messages. For batteries that need a lot of help, the 4.3 may be the best CTek choice, as it has more profiles.

So the moral of the story, I’m afraid any modern car doing short trips or in the winter needs to spend some regular time on a smart maintainer-charger, otherwise you’ll see shortened battery life and potential starting issues. How often you should do this, I don’t know.

[bimmer_girl89]

Originally Posted by Cumberlandjames

Just curious as to where the charger was mounted or was it just in the car loose? Never heard of one being included, mine didn't come with one.
thanks

I am not sure how or where it is actually mounted. I have a power cable that I attach to the car (see photo below) and that's how I charge it. I could be wrong but it might be part of the cold weather package or maybe it's extra but when I bought the car, it already had it (same with the two previous F30's I've had).

[bimmer_girl89]

A charger from the factory must be a unique Canadian option. Makes sense, and you definitely get different options than we do in the US. It would be a nice option for us in Minnesota.[/QUOTE]

Must be. It could be part of the cold weather package but I think the dealer can install these for you. My dealer advertises it at heir shop.

[Kolyan2k]

My car is in right now for some services including this battery msg. maybe they'll fix something. funny that my s2k battery was original after 10 years and 90k miles, still started the car fine even in new england cold